Multiple wire feed mechanism



3 Sheets-Sheet 1 \NNX Mm A. E. VANDERSEE MULTIPLE WIRE FEED MECHANISM Filed May 25, 1944 Jah. 14, 1947.

771024 Edmund Z knaersee Jan. 14, 1947. A. E. VANDERSEE 2,414,181

MULTIPLE WIRE FEED MECHANISM Filed May 25; 1944 s sheets-sheet 2 ZNVENZUg zald Edi/alum Vmzdersee Jan. 14, 1947. A. E. VANDERSEE MULTIPLE WIRE FEED MECHANISM Filed May 25, 1944 3 Sheets-Sheet 3 wQ wk zoZd Edmund hndersee Patented Jan. 14, 1947 2,414,181 MULTIPLE WIRE FEED MECHANISM Arnold E. Vandersee, Chicago, Ill., assignor of one-half to Henry W. Dieringer, Chicago, Ill.

Application May 25, 1944, Serial No. 537,293

(01. ill-42.2)

12 Claims.

' This invention is directed to an improved metallizing gun of the spray type and relates more particularly to an improved wire feed mechanism therefor.

It is an important object of the present invention to provide in a gun of the above character, an improved mechanism for feeding the wire thereto, this wire to be melted and discharged from the nozzle of the gun in a highly comminuted state.

It is another object of the present invention to provide, in a metallizing gun, an improved wire feed mechanism capable of delivering to the device an increased amount of metal per unit of power input.

It is still another object of the present invention to provide an improved wire feed for a metallizing spray gun which is capable of advancing a greater volume of wire per unit of power input than has been customary in the past.

' Another object of the present invention is to provide an improved wire feed mechanism for a metallizing spray gun which is efficient and compact and yet is capable of advancing through the gun, a plurality, preferably four strands, of wire to be sprayed.

In the past many efforts have been made to increase the volume of wire which could be fed to a spray gun in order that the spraying or metallizing operation could be accomplished more rapidly. One expedient which has been attempted heretofore involves an increase in the diameter of a single strand of wire fed to the gun. However, this arrangement has proved unsatisfactory since it was found that the wire melting arrangement merely melted the outer part thereof and was unable to transform the core of the wire to molten condition. Under these circumstances it was found that while the wire disintegrated into comminuted form around the outer portion thereof the core remained intact and was constantly fed forwardly and out of the nozzle of the gun as a wire of reduced diameter. This, of course, involves a tremendous waste of metal and failed to provide the additional volume of molten material which was required.

More specificaly, it is an object of the present invention to provide a multi-strand channel through a metallizing spray gun for conducting a plurality of strands therethrough, certain of these strands being engaged by an advancing mechanism at one point of their progress through the gun and others of the strands being engaged by a second advancing mechanism at another pointin their advance through the gun.

In accordance with the general features of the present invention there is provided herein a metallizing spray gun having any suitable source of power such as a turbine or the like, the turbine being arranged to rotate and drive a jack shaft which in turn extends longitudinally in the gun and is provided with worms at longitudinally spaced points thereon. Each of these worms is in line with a wire advancing mechanism, one of which advances vertically disposed strands of wire inserted in the gun and the other of which advances horizontally disposed wires. these advancing mechanisms is disposed normal to the other and is provided with spaced, knurled wire gripping wheels which are opposed to similar wheels driven thereby on a suitable bearing. As one of said advancing mechanisms grips one set of wires, the other set is disposed between the knurled gripping wheels thereon to pass freely therebetween so that at one point on the longitudinal axis of the gun certain of the wires are advanced and others idle between the advancing wheels while, at another point on the longitudinal axis of the gun, the remaining wires are advanced while those engaged by the first named gripping wheels pass therebetween toward the nozzle of the gun.

It is still another object of the present invention to provide an improved wire advancing mechanism for a metallizing spray gun wherein the wire gripping, advancing wheels are rockably associated to permit the tight gripping and advancing of wire stock in the presence of slight variations in diameter thereof.

It is still a further object of the present invention to provide a metallizing spray gun of the above character which is susceptible of economical manufacture, is compact and may be easily and eificiently operated by a relatively unskilled user.

It is a further object of the present invention to provide an improved nozzle for a metallizing spray gun, such nozzle including passages for receiving a plurality of strands of wire for passage therethrough and also including gas passagestherethrough which are so disposed that each of the strands of wire is subjected to heating action on all sides when gas emitted from the respective gas passages is ignited.

Still a further object of the present invention is to provide a nozzle of the above character having a central longitudinal gas passage, which has gas fed therethrough through a plurality of passages, and which is provided with a restricted outlet thereby to afford an improved nozzle effect.

Each of The present improvements also contemplate a novel arrangement of the wires around a common center, and having individual feeds for transversely disposed pairs of the wires. The improvements also contemplate an arrangement whereby a plurality of wires leaVing the nozzle of a metal spraying gun will each be surrounded by hot burningg-gases' whereby the entire super-- ficial areaf each wire will be affected by the burning gases to cause an equal and complete melting of each wire as it leaves the nozzle of.

th spraying gun.

It is one of the principal objectsofthis invention to simplify the constructionzof a multiple" wire feed mechanism such as contemplated herein, and to improve the efi'iciency,,operation and dependability of such wire feed mechanism;

It is also a. principal object of this invention.

to provide a wire feed .mechanism that is of a dual-feed-type wherein a pair of wires. may be simultaneously advanced to a metalv spraying.

nozzle-regardless of variations in diameters of the respective wires; and alternatively two pairs of wires may be simultaneously fed to a nozzle device in the same apparatus.

Another'principal object of this invention is to provide a metal spraying gun with a plurality. of

wire feed units wherein each unitis adaptedto feed a pairof side-by-sidewires.

Afurther principal object hereof is to provide afplurality ofwire feed units arranged in tandem.

fopadvancing pairs ofwiresor the like, and each unit having provision for: the-uninterrupted free passage-of another pair of wires past the same.

Another object hereofis to provide a wirefeed mechanism wherein at least one of the wire advancing: rollers, or a pairof-rollers, is yieldably.

urged towards the. opposing roller or pair of rollers and to providea tiltable'carrier. for the yieldably urgedfroller or pair ofrollers whereby.

th'efeed will automatically accommodate itself to variations in diameters of th wire or wires being,

fedby the. device or to feed. wireslof different gauger A further object is .to provide means for feeding a plurality of wires through" a.metal spraying gunnozzle in concentricarrangement around a centralgas discharge port that is supplied with combustiblegas from aplurality. of -radially disposed inlet passages, such central port being; augmentedby a. series. of other gas discharge portsthat varearrangedin groups. around each wire leaving its respective guide. in. the nozzle. This arrangement positively insures the melting ofallssides of each individual'wire and it also effects thecomplete .and simultaneous fusingv of a. plurality: of wires. inla. single metal spraying. nozzle.

Still another principal object of this invention. is .to provide means in a metal spraying apparatus for= effectively formingv an alloy of a plurality. of metals at the nozzle-and spraying the alloythus formed; With the arrangementherein disclosed the-formingand spraying. of a. metal alloy is readilyaccomplished byadvancing a plurality of wires of different metals to the nozzle by multiple feed. means and regulatingthe. speedLoftravel of such wiresvwith relationto the-respective fusing-points of the different metals forming-the alloy.- Thismerely involves the changing of gear or speed ratio of the different gearassembliesafter fully described and as more particularly pointed out in the appended claims, reference being made to the accompanying drawings that form a part of this specification.

In the drawings:

Figure 1 is a longitudinal vertical section taken axially through a metal spraying gun showing the present improvements incorpiorated therein.

FigurecZAisL a vertical transverse section taken on the plane of line 11-11 on Figure 1 showing details of one of the multiple wire feed units and a portion .of .the drive therefor.

Figure3 isa 'vertical transverse section taken on: theplane of linelII-III on Figure 1 showing details: of the. second: multiple wire feed unit and a portion of thedriving means therefor.

Figure 4'is "a face elevation of the rear end of thenozzlebody detached from the apparatus and drawn to an enlarged scale.

Figure 5 is a longitudinal .sectiontaken on the Cir two planes of line V-V on Figure: 4. and looking.

in the direction of .the arrows.

Figure 6 is a face elevation of the front end Figure '7 is an axialnsection. of a yieldable; clamping device employed in the present apparatusa Figure 8 is an end view of'the end of aboss on the head'of the spray gun body or housing.

The drawings are. tube-understood as being.

more or less of a schematic character for the purpose of disclosing. atypical or preferredform of the improvements contemplated herein. In thesedrawings like reference charactersidentify the same Parts inthe several .views.

The embodiment. of the metaltspraymg un shownin the drawings comprisesa body lllof.

asymmetric or. irregular shape, preferably acast- 4;) ing or thelike, the front or work-end portion of which hasa flat transverse faceto. which av jects. axially from the head 'H and is of such. length that it extends beyond thewasher M in.

the mannershown inFigurel; The diameter. of this boss I5". is Iessthan the inside diameter of the. washer M to provide anannular. outlet passageway i6 for the chamber Hthat isformed. by:

thelannulanflangen and thewasher M. The: atomizing. air for. the. nozzle. .is discharged. into. chamber 11 through a feedpassagewayl'la. in the head I I, saidlfeedpassageway being under. con-- trol of the valve ..l la -to supply; pressured. airfrom a suitable .source..

The-body H3, at itsendfopposite theheadll;

is. provided -with1.a. longitudinal bore 1 (Mo. receive.

a .wire guide orbushingsl 9 thatis secured in place byaclampscrew 20;, The wire guide or bushing.

l9"h'as preferably four equidistantly.spacedchannelsl2l that providelongitudinall guides for-two.

pairs of wires. 22a-and=22b .thati are arrangedv radially aroundsaicommon center, the. wiresv of onelpair being .vertically disposed. and the wires. of the other. pair beinghorizontally disposed; as.

seenin' Figures. 2 .and 3.

nasal-shouldered borei23j disposedfin axial align.- ment. with the bore I 8 r at then-other end. of.v the body. A flanged wireguide orbushingzll is seated in theshouldered bore 23 and is provided with a plurality of axial channels 25; preferably four" The-.end of. thebody. lnla d'jacent the. head .1

in number, that correspond in arrangement and are axially aligned with the bores 2I in the other wire guide or bushing I9. The head II is provided with a shoulderedbore 25 to receive a reduced portion of the bushing 24, said bore 25 being extended also into the adjacent end of the boss I5 of the head. The means which clamp the head I! to the flat forward face of the body I are adapted to draw the head against the shoulder portion of the bushing 24 and clamp it against the shoulder in the bore 23 of the body thereby providing a rigid construction and assembly. The wires 22a and 22b in passage to bushing 24 will span the open recesses 21 and 28 in theportion of the body between the inner ends of the bushings I9 and 24. These recesses 21 and 28 are made in the body to receive and accommodate a plurality of wire feeding units that will be presently .described.

The rear end of the body I6, the left end as observed in Fig. l, is provided with a cylindrical housing 29 constituting a rotor or turbine chamwhich is extended into a chamber 32 in the adjacent portion of the body and to the rear of the recess 21 before mentioned, i. e. to the left as in Fig. 1. Within the chamber 32 the turbine shaft 3| has a worm 33 anchored to it that meshes with a worm wheel 34 on the adjacent portion of a jack shaft 35 disposed at right angles to the turbine shaft. The jack shaft 35 extends longitudinally within the body I6 through the two recesses 21 and 28 and has its ends journaled in anti-friction bearings 31 and 38 in the inner portions of hollow plugs 39 and 46 which are screwed into openings in the respective rear and front ends of the body ID in the manner shown in Figure 1. The turbine 30 is driven by pressure fluid that is admitted to the rotor chamber 29 through an input passage 29a in a convenient portion of said housing 29 that communicates with a turbine air branch 29b in the head I I, which branch receives pressure fluid through a multiple control valve Ila.

The jack shaft 35 is provided with a worm 4I beneath the feed unit for the horizontal pair of wires 22b. This worm 4I meshes with a worm wheel 42 secured to a transmission shaft 43 that is journaled intermediate its ends in anti-friction bearings 44 that are suitably secured in a bearing opening 45 made in the adjacent wall of the recess 21 so that the shaft 43 projects across the lower portion of recess 21. The outer end of the transmission shaft 43 is journaled in anti-friction bearings 46 carried in a cupped plug 41 that is screwed into a bearing opening 48 in the body I 9. An end thrust spring washer 49 is seated in the cupped plug 41 back of the anti-friction bearing 46 and the other end of said shaft is provided with an end piece or head 50 having a central knob that presses against a hard metal disk 52 in a seat 53 axially aligned with the shaft 43.

- Within the recess 21 the transmission'shaft 43 has a gear 54 secured to it, and between this gear and the head or end piece 59 there is a pair of side-by-side spaced feed rollers 55 having knurled or corrugated cylindrical faces for engagement with the respective wires of the horizontally disposed pair 22b. The opposing side-by-side pair of knurled rollers 56 are disposed in spaced relation to each other on a spindle 51 that is provided with'a gear 58 that meshes with the gear 54 on to their axis of rotation to accommodate inaccu-v 5 racies or differences in diameter of the jpairof wires 22b with which these rollers are engaged. A suitable carrier 59 of hollow construction is provided with bearings for the roller spindle 51, and the upper portion of this carrier has a boss 60 for pivotally or swingingly mounting carrier 59 upon a pivot pin 6| the ends of which project through the boss 66 and are suitably secured in the adjacent hollow portion of presser arm 62. As seen in Figure 2 the carrier 59 has a somewhat yoke-shape and the bearings for the spindle 51 are in the lower portions of the side members of this yoke. The presser arm 62 on. which thecarrier 59 is swingingly mounted is fulcrumed at its end opposite the carrier 59 upon a pivot pin 63, thus permitting the arm to lift the carrier 59 for disengaging the upper feed rollers 56 of this feed unit from the opposing feed rollers 55 that rotate upon a fixed axis.

Means are provided for yieldably urging the upper rollers 56 of the feed unit in opposition to the lower feed rollers 55. Intermediate its ends the presser arm 62 is provided with a smooth bored opening 64 to receive the smooth shank portion of a tightening bolt 65 having threads upon its lower end portion that screw into a threaded boss 66 on the adjacent portion of the body In alongside the top of recess 21. The bolt 65 is a part of a yieldable clamping assembly that is adapted to urge the arm 62 in a downward direction so that the rollers 56 on the swinging carrier 59 will be pressed firmly against the hori-- zontal pair of wires 22?). i

The details of this clamping assembly are shown in Figure 7 where it 'will be seen that the upper portion of the bolt 65 is reduced in diameter and is threaded at its upper end to screw into the upper end portion of a hollow sleeve 61. The lower portion of the sleeve 61 bears against the arm 62 around the bore 64 through which the bolt passes. Between the upper and lower threads on the bolt there is a shoulder 68 to re-,

ceive a follower ring 69 and interposed between this ring 69 and the upper end of the wide bore of the sleeve 61 there is an expansion coil spring 10 the tension of which is tightened by screwing the sleeve upon the end of the bolt 65 aft-er the lower threaded portion of the bolt has been engaged in the threads of the boss 66. After proper adjustment of the spring has been made a cotter pin H is inserted through an upstanding boss 12 at the top of the sleeve 61, which cotter pin is passed through a longitudinal slot 13 in the upper portion of the bolt thus securely looking the bolt and sleeve against relative rotation while maintaining the spring 16 under the desired tension. When this clamping device is screwed into boss 66 with the sleeve 61 engaged against the arm 62, the spring 19 will be under increased tension so that the rollers 56 are yieldably urged towards rollers 55. Furthermore, the carrier 59 may rock upon th pin 6I should there be any unevenness in either of the horizontal pair of wires 22b that are passing between the opposing rollers 56 and 55.

0 The jack shaft 35 adjacent its front bearing 38 is provided with a second worm 15 that drives a worm wheel 16 on a vertically disposed transmission shaft 11. The lower reduced end portion of transmission shaft 11 is journaled in antifriction bearings 18 seated in a cupped plug 19 amnesia thati is screwed into a th-readedlopenin'g Basin-z the lower portion of the b'ody 'l This-worm andl worm wheelatogether -with the transmission shaft IT: are: in the lower 'portiorr of the recess- 28 and I immediately above the 'h'ubof wonn wheel "I 6 the transmission shaft l-ll is j our-naled in anti-fric tion bearings 81 as shown in Figure-31* Theupper plate 85 in the manner' shown. Above its bearing Bl the transmission shaft? 'l'l'h'as a gear 85- anchored to'it, and-between this gear and the end piece SZ is a side-by-side -pair of knurled "feedrollers" 86 arranged in spaced' relation the one abovethe other;

the spray gun.

The gear 85 of this second feed unit is meshed with a gear 88 carried upon the lower end'of a Vertical spindle 89, parallel to shaft TI that'is journaled at its end in bearings on a yoke-shaped carrier 99 that is similar to the carrier 59 of the feed unit that advances the horizontally arranged p'airtof wires 22b; Thespindle 89 has secured to' ita' pair-'of spaced knurled feed rollers BI ar ranged'in opposition to the rollers 85: on the transmission shaft 11; The carrier 90 has a boss 92 whereby it is swingingly mounted upon a pivot' pin'93 mounted in spaced opposite portions of an arnrB l. The arms? is in a vertical position and has its lower end portion fulcrumed upon a pivot pin 95icarried in a boss 96 upon the adjacent portiontof the body Ill. The arme is yieldably urgedin adirection to oppose the rollers SH 't0- wards the rollers" 86 with'thewires 221': between them; I The'means for urging the .arm in a direction to grip the wires 22a comprises a clamp assembly similar to theclamp shown: in Figure 7 wherein the smooth shank portion of a bolt 91' passes through a smooth bored hole 58 in the arm EM'andchas its. threaded end portion 99' screwed into a threaded recess Ifillin the aligned portion of the body Ill asshown in Figure 3. i The remaining portion of this clamping assembly is similar to that shown in Figure '7 and 'the details thereof may be here omitted;

The feed units, .as hereinbefore described, are

preferably arrangedone ahead of the other in the direction of wire travel, and each pair of rollers maybe of the Siamese type. The space between the opposing Siamese rollers 55"and 56 provides a channel it: to accommodate the vertically disposed pair of'wires 22a'and permits free uninterrupted movement of this pair of wires 22a past'this feeding unit which advances the horizontally disposedpair of wires 22b'towards the nozzle.

pair of wires 22a to the nozzle.

The arrangement hereinbe-fore described per- This is a secon'd wire-feed unit that is adapted to advancethe second or vertically disposed pair of wires 22a: to the nozzle end of In a similarmanner thespaces Hi2 between'the opposing Siamese rollers Strand-"QI- of the second'unit provide for the free passage of the horizontally disposedpair of wires"22b" past thissecond unit which advances the vertical irigzttwowiresrtozthe: nozzles. A'lsodftit lswadesiredo to: provide: a spraywhichi. is an'ri alloy; ofstwo; metals, one pair off'wires may be? of: one imetaln and the' oth'er 'pair of'wiresi'may be of? another? .1 metal, forming .the' respectivevcomponentsrofithet alloy desired; The wires being ofidifierentdensityf an'di having" difierent fusing points will I requires different: feeds for advancing; them to the'unoz zle" and this difierential of. feeds may'becon' trolled-by merely'changingr. the v gear: ratio' of at worm and worm wheelof one or both of thezref-r spective feed. units; This adapts'th'e machine:- for 'a' wi'de range of usefulness 'andwithout alteriing its mode of1operation.

The components of the oxyacetylene: gas for:

the'nozzle are received from suitable sourcesand: areirseparately"fedlfrom. valve: Ila" into" a; mix-:-

ing chamber I03: in' the head II, from whlclrl they enter a branch I04 leading through theboss'r i: I51ofatheheadgas'shown in'Figure'l, tobe-dlscharged into an annular channel orchamberLIllS infthe fend vface of said :boss.

Th'eanozzle of the spray gun comprises1a2:b'0dy- I OBI having: a: cylindrical portion and a tapered:

"-, portion; the: latter having a plurality 'of elon' gaged airichannels I01 cutilongitudinally inits: surface. An annular flange? I08 afiords meansi' whereby the body llltmay betmountedflin abut ting relation to the 'channeledend" face ofthes boss I5 by means of clamping collar: I09 that isi screwed upon the exteriorly threaded portion of saidboss: The body [060i theinozzleassembly has" a" plurality 'of longitudinally disposed par; allel. bores I10; preferably four in number; ar

, ranged radially around-a common:center to" pr'ovide; guides? for the 'two' pairs of. wires 22a; and" 22b. Th discharge ends of: the bores- Illlihaves bushings III inserted therein to; reduce their;

- thanithe gaugeofithe wires p'assingitherethrough;

Theother'ends ofithese bores IIII areregist'eredf with *the respectivebores 25 that g'uide the wireszz through the? boss: I5 of the-head I I.

A plurality of obliquely disposed gas passage ways" H2 are bored'longitu'dinally throughttheu body 2 I 06-: in" the manner showniin Figure :5::an'd have their outlet end portions reduced as at; I I3 to. provide jet-:forming. mouths." The 1 inlet portions of these gas' passageways I I2' communicaterwith the annular channel l05a ini'the end: of boss-I 5 and receive the oxyacetylenegasthere-w from-.- There is also. aicentra'l or axialgasvpase' sageway I I4 extending part way through the body; I06: and provided at itsdischarge end with 3Z1. jet-formingbushing I I5: The inlet: endzxof this; passageway I I4" communicates by: aplurality of; branches'llfi leadingfrom the inlet'ends of;thet: oblique gas passageways H2; Other. obliquely: disposed; passageways: II 1,: having; reduced jet3+= forminggmouthsi I I8 are boredobliquely:throughthe body I06; as shown in' the upper: portion of; Figure 5; andhavetheir inlet ends'communieating with theannular chamber in the end; of :the :boss -1 I 5.x

The cap which surrounds the nozzle: body I 06: is lot tapered design .in longitudinal section and comprises a frusto-conical ontapered skirt I20; having, an interiorly threaded v flange v. I 20-61 i at its. base portion that is shouldered andis; screwed upon' the threaded exterior of the? flange I2off theih'ead, with its shoulder pressed'against the washer? I 4to 'maintain'th'e latteriin position; The other "portion or -the" cap comprises: 'a' tapered or frusto conical tip: I22 having a threaded'cylin'idrical 1 base I 23 that is screwed" into the; adja 3 9 cent threaded end of the skirt portion I20. The tapered interior surface of the tip corresponds withthe tapered surface of the body I06 and it is screwed intothe skirt portion until these tapered surfaces engage each other so that the atomizing air will pass through the longitudinal channels 101 to be discharged into the end of the tip that projects beyond the end face of the tapered body I06, as shown in Figure 1. Un-

screwing the tip I22 will, of course, increase the size of the air passage to vary the atomizing function.

By reference to Figure 6 'it will be seen that the four wires leaving the nozzle body I06 are surroundedby a plurality of streams of-ignited gases. All of the wires leaving their guides Ill receive a portion of the flame from the central jet H5, and each wire also receives the flames of two of the jets H3 as well as one ofthe jets ll8'that may be said to be individual to each wire; The jets are concentrically arranged around a common centerat the axis of thecentral jet ll5.- Thus, each wire is subjected to gas flames from at least four jets, with the result that the whole exposed surface of each wire is affected by flames that are directed towards it from a plurality of directions. Hence the fusing of the metal is complete and extremely rapid and therefore the feed of the wire may be materially increased in speed well above the speed heretofore employed in spray guns. Furthermore, the central jet is rendered extremely efficient, due to the fact that substantially all of the ignited gases issuing therefrom is utilized against metal issuing from the several wire guides around the central jet.

It will also be apparent that the two wires or two pairs of metal wires having different fusing or melting points may be fed through the gun and sprayed at the nozzle in the form of an'alloy of two or more metals.

It will, of course, be understood that various details of construction may be varied through a widerange without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. A spray gun for spraying metal from a pair of metal wires comprising a housing; a nozzle at an end of said housing; and means for advancing the pair of wires through said housing to said nozzle comprising a first pair of side-by-side feed rollers rotatable on a fixed axis; a second pair of side-by-side feed rollers opposing the rollers of said first pair; means for driving said pairs of feed rollers in unison; a carrier in which said second pair of feed rollers are journaled; a yieldable arm fulcrumed on aid housing; and means swingably mounting said carrier on said arm to thereby adapt said second pair of feed rollers for rocking bodily movement transverse to the line of travel of the wires to accommodate opposing rollers to variations in the respective wires.

2. A spray gun for spraying metal from a plurality of pairs of metal wires comprising a housing; a pair of vertically spaced guides in said housing; a pair of horizontally spaced guides in said housing; a nozzle at the delivery end of said housing having bores registered with said housing guides for receiving wires fed therethrough; a first feed unit in said housing including a pair of Siamese rollers rotatable on a fixed axis; an

opposing pair of Siamese rollers yieldably urged towards the other Siamese rollers, said. pairs of rollers arranged upon horizontal axes in superposed relation for gripping and advancing the horizontal pair of wires to said nozzle with the vertical pair of wires freely movable in a space between the respective upper and lower Siamese rollers; a second feed unit including a pair of Siamese rollers rotatable on a fixed vertical axis; an opposing pair of Siamese rollers rotatable on a vertical axis and yieldably urged towards the other Siamese rollers having a vertical axis, the rollers of said second unit adapted to grip and advance the vertical pair of wires to said nozzle with the horizontal pair of Wires freely movable in spaces between the respective Siamese rollers of the second feed unit; a prime mover, a shaft driven by said prime mover; and geared means operatively connecting said shaft to the respective first and second wire feed units.

3. A spray gun for spraying metal from metal wire comprising a housing; a plurality of wire guides through said housing arranged in diametrically disposed pairs; advancing means engaged with one pair of the wires at one point in the travel of said pair through said housing; another advancing means engaged with a second pair of wires at a point in their travel through said housing that is removed from the point of engagement of the first pair of wires; a prime mover; and transmission means operatively connecting the respective advancing means to said prime mover for simultaneously moving all of the wires through said housing. I

4. In a spray gun for spraying comminuted metal fed thereto as wire, means forguiding a plurality of strands of wire through the gun and means for advancing said strands including a plurality of advancing mechanisms comprising opposed circular feed members, each fed member having spaced wire gripping portions and intermediate portions for receiving in free, non-engaging relationship wire advanced by another like "advancing mechanism.

5. In a nozzle for a spray gun of the type 0 adapted to spray metal from a plurality of wires fed thereto, a plurality of wire guide channels, a central gas passage having an outlet surrounded by outlets of said wire guide channels, a plurality of radial gas passages having outlets surrounding each wire channel outlet whereby substantially all of the ignited gas from said central gas outlet is impinged upon the wires to melt the same and the ignited gas from the radial gas outlets melts the outer sides of the Wires, and an annular air pressure stream around all of the gas passage outlets and converging inwardly to aid combustion of the gases and atomization of the metal.

6. In a spray gun for-spraying comminuted metal fed thereto as wire, means for guiding a plurality of strands of wire through the gun and means for advancing said strands including a plurality of sets of feed rollers, the axes of the rollers of each set being at right angles to the direction of wire movement and also at right angles to each other, one setbeing disposed so that the rollers thereof engage with and advance a first strand of wire and so that a second strand is aligned with the space between said rollers and another set being disposed so that the rollers thereof engage with and advance the second strand and so that the first strand, advanced by the first named set of rollers is aligned with the space between the rollers thereof.

sets of-feed rollers arranged onegahea'd JOf'f the wothernin the direction 'of-wire travel, each;.set including two pairs .of opposed'rollers with the :axesof the rollers of one. set horizontal and the axeslof the rollers of the otherset verticalga pair Ofi opposed rollers'adapted to separately grip;

.and::adva-nce one of the wires .to saidlnozzle; --separate;gearingt for: rotating each pair of each a set of-lsaid feed IOHBIS'iiO independently: advance qsa-id wires; and means for, actuating; said gearing.

8. "-Asprayggun. for sprayinggmetal; from metal .-.a.common center, a .nozzleat the dischargeend of. saidguides imeans: for advancing a plurality of wires through said guides comprising two sets :ofieed rollers "arranged one ahead of the other in the direction of Wire travel, each set including .two pairs of opposed-rollers With the axes of the rollers of one set horizontal and the axes of --th .otheret vertical, apair of opposedcrollers adapted to grip and advance 'one of the wires to r-said nozzle; separate gearing for rotating each :pair of each-set of said feed rollers tot-independventlyadvance said wires; and emeansionactuating said gearing.

9. -A spray gun for-spraying metal from metal '-Wirecomprising a housing; a pluralityof'wire 12 z-ofimetal wireszcomprising a; housingma plurality :iofwireuguidesa throughgsaid: housing; :zadvancing cmea'nsi engaged with certain ofrtheswiresatione ;.point; in w their travel ;through: said: housing; anr-otheradvancing.means engagemwithmther-wires r at apointr ahead-.ot the point: of engagement-of 115 wire v comprising a housing; a plurality s of wire g guides through said .housing arranged around ssaid-vfirst mentioned-advancing; means ew-ithisaid certain-wirestakenrinthe.Ldirection-of.;wire:move- ...ment; a pri-me rmover; sand transmission emeans toperatively connecting tthe ir espective: advancing .imeansitoisaidprimelmover.

'11. 'In a nozzle for aspray gun-of the r-gtxpe adapted, togspnaymetal-rfrom, a pluralityuof rwires 1 passing through it,ccomprisingsrmeanslvformingaa plurality. of =wnire;;g=uide.::channels means;.-formin g aaicentral gas-passagelhavingaanioutletcsurrounda ed Jay the :outlets eof said -wire-g7-g11ide cchannels, =means providingla plurality ,ofi'rajdial H gas passages 7 :having out-lets :surrounding .zeach (10f 'the .wvire (channel ,outlets whereby substantially all laof athe ignited: :gas from the .said icentral 'gas outlet strikes the wiresl-toamelt .theisame-sand them-ignited gas. from vthe .1-radial gassoutlets melts the outer surf acesl-of the s wires, and, means providing an annular. air pressure ,stream...around call of the gas passageloutlets andiconuergingbinwardly to raid combustion -of lther, gasesarida-tomization of the metal.

:12. In a. spray, gun Lifer spraying :ccomminuted metal Ife'd thereto .la's "wirajimeansf forl, guiding a plurality of strands .of wire ithrou'gh litheggun, means for iadvancingla' pair. of wiresing parallel and laterally spaced relation,i'means' fona'dvanc- Zinga secoridpair of wiresjinparallel and laterally spaced relation with, the; ,planeuof-the secon'dpair "of wires at an angle'to 'the;plane of the'hr'st pair of wires, the. arrangementJbeing (such, that the advancing meansiforonenpair of .wiresstraddles.tthe planeiof thejothergpairj of wires. to thereby providei free ,passageof Sai d'JOnQ p aiTiOf wires 'with 'respect to the other advancingmeansuas said one, pair o'fwires" is moved by-its advancing means.

i ARNOLDTE." 'VANDERSEE. 

